xref: /netbsd-src/sys/net80211/ieee80211_output.c (revision de1dfb1250df962f1ff3a011772cf58e605aed11)
1 /*	$NetBSD: ieee80211_output.c,v 1.17 2004/08/10 00:57:22 dyoung Exp $	*/
2 /*-
3  * Copyright (c) 2001 Atsushi Onoe
4  * Copyright (c) 2002, 2003 Sam Leffler, Errno Consulting
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. The name of the author may not be used to endorse or promote products
16  *    derived from this software without specific prior written permission.
17  *
18  * Alternatively, this software may be distributed under the terms of the
19  * GNU General Public License ("GPL") version 2 as published by the Free
20  * Software Foundation.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
23  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
24  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
25  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
26  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
27  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
31  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32  */
33 
34 #include <sys/cdefs.h>
35 #ifdef __FreeBSD__
36 __FBSDID("$FreeBSD: src/sys/net80211/ieee80211_output.c,v 1.10 2004/04/02 23:25:39 sam Exp $");
37 #else
38 __KERNEL_RCSID(0, "$NetBSD: ieee80211_output.c,v 1.17 2004/08/10 00:57:22 dyoung Exp $");
39 #endif
40 
41 #include "opt_inet.h"
42 
43 #ifdef __NetBSD__
44 #include "bpfilter.h"
45 #endif /* __NetBSD__ */
46 
47 #include <sys/param.h>
48 #include <sys/systm.h>
49 #include <sys/mbuf.h>
50 #include <sys/malloc.h>
51 #include <sys/kernel.h>
52 #include <sys/socket.h>
53 #include <sys/sockio.h>
54 #include <sys/endian.h>
55 #include <sys/errno.h>
56 #ifdef __FreeBSD__
57 #include <sys/bus.h>
58 #endif
59 #include <sys/proc.h>
60 #include <sys/sysctl.h>
61 
62 #ifdef __FreeBSD__
63 #include <machine/atomic.h>
64 #endif
65 
66 #include <net/if.h>
67 #include <net/if_dl.h>
68 #include <net/if_media.h>
69 #include <net/if_arp.h>
70 #ifdef __FreeBSD__
71 #include <net/ethernet.h>
72 #else
73 #include <net/if_ether.h>
74 #endif
75 #include <net/if_llc.h>
76 
77 #include <net80211/ieee80211_var.h>
78 #include <net80211/ieee80211_compat.h>
79 
80 #if NBPFILTER > 0
81 #include <net/bpf.h>
82 #endif
83 
84 #ifdef INET
85 #include <netinet/in.h>
86 #ifdef __FreeBSD__
87 #include <netinet/if_ether.h>
88 #else
89 #include <net/if_ether.h>
90 #endif
91 #endif
92 
93 #ifdef IEEE80211_DEBUG
94 /*
95  * Decide if an outbound management frame should be
96  * printed when debugging is enabled.  This filters some
97  * of the less interesting frames that come frequently
98  * (e.g. beacons).
99  */
100 static __inline int
101 doprint(struct ieee80211com *ic, int subtype)
102 {
103 	switch (subtype) {
104 	case IEEE80211_FC0_SUBTYPE_PROBE_RESP:
105 		return (ic->ic_opmode == IEEE80211_M_IBSS);
106 	}
107 	return 1;
108 }
109 #endif
110 
111 /*
112  * Send a management frame to the specified node.  The node pointer
113  * must have a reference as the pointer will be passed to the driver
114  * and potentially held for a long time.  If the frame is successfully
115  * dispatched to the driver, then it is responsible for freeing the
116  * reference (and potentially free'ing up any associated storage).
117  */
118 static int
119 ieee80211_mgmt_output(struct ifnet *ifp, struct ieee80211_node *ni,
120     struct mbuf *m, int type)
121 {
122 	struct ieee80211com *ic = (void *)ifp;
123 	struct ieee80211_frame *wh;
124 
125 	IASSERT(ni != NULL, ("null node"));
126 	ni->ni_inact = 0;
127 
128 	/*
129 	 * Yech, hack alert!  We want to pass the node down to the
130 	 * driver's start routine.  If we don't do so then the start
131 	 * routine must immediately look it up again and that can
132 	 * cause a lock order reversal if, for example, this frame
133 	 * is being sent because the station is being timedout and
134 	 * the frame being sent is a DEAUTH message.  We could stick
135 	 * this in an m_tag and tack that on to the mbuf.  However
136 	 * that's rather expensive to do for every frame so instead
137 	 * we stuff it in the rcvif field since outbound frames do
138 	 * not (presently) use this.
139 	 */
140 	M_PREPEND(m, sizeof(struct ieee80211_frame), M_DONTWAIT);
141 	if (m == NULL)
142 		return ENOMEM;
143 #ifdef __FreeBSD__
144 	KASSERT(m->m_pkthdr.rcvif == NULL, ("rcvif not null"));
145 #endif
146 	m->m_pkthdr.rcvif = (void *)ni;
147 
148 	wh = mtod(m, struct ieee80211_frame *);
149 	wh->i_fc[0] = IEEE80211_FC0_VERSION_0 | IEEE80211_FC0_TYPE_MGT | type;
150 	wh->i_fc[1] = IEEE80211_FC1_DIR_NODS;
151 	*(u_int16_t *)&wh->i_dur[0] = 0;
152 	*(u_int16_t *)&wh->i_seq[0] =
153 	    htole16(ni->ni_txseq << IEEE80211_SEQ_SEQ_SHIFT);
154 	ni->ni_txseq++;
155 	IEEE80211_ADDR_COPY(wh->i_addr1, ni->ni_macaddr);
156 	IEEE80211_ADDR_COPY(wh->i_addr2, ic->ic_myaddr);
157 	IEEE80211_ADDR_COPY(wh->i_addr3, ni->ni_bssid);
158 
159 	if ((m->m_flags & M_LINK0) != 0 && ni->ni_challenge != NULL) {
160 		m->m_flags &= ~M_LINK0;
161 		IEEE80211_DPRINTF(ic, IEEE80211_MSG_AUTH,
162 			("%s: encrypting frame for %s\n",
163 			__func__, ether_sprintf(wh->i_addr1)));
164 		wh->i_fc[1] |= IEEE80211_FC1_WEP;
165 	}
166 #ifdef IEEE80211_DEBUG
167 	/* avoid printing too many frames */
168 	if ((ieee80211_msg_debug(ic) && doprint(ic, type)) ||
169 	    ieee80211_msg_dumppkts(ic)) {
170 		if_printf(ifp, "sending %s to %s on channel %u\n",
171 		    ieee80211_mgt_subtype_name[
172 		    (type & IEEE80211_FC0_SUBTYPE_MASK)
173 		    >> IEEE80211_FC0_SUBTYPE_SHIFT],
174 		    ether_sprintf(ni->ni_macaddr),
175 		    ieee80211_chan2ieee(ic, ni->ni_chan));
176 	}
177 #endif
178 	IF_ENQUEUE(&ic->ic_mgtq, m);
179 	ifp->if_timer = 1;
180 	(*ifp->if_start)(ifp);
181 	return 0;
182 }
183 
184 /*
185  * Encapsulate an outbound data frame.  The mbuf chain is updated and
186  * a reference to the destination node is returned.  If an error is
187  * encountered NULL is returned and the node reference will also be NULL.
188  *
189  * NB: The caller is responsible for free'ing a returned node reference.
190  *     The convention is ic_bss is not reference counted; the caller must
191  *     maintain that.
192  */
193 struct mbuf *
194 ieee80211_encap(struct ifnet *ifp, struct mbuf *m, struct ieee80211_node **pni)
195 {
196 	struct ieee80211com *ic = (void *)ifp;
197 	struct ether_header eh;
198 	struct ieee80211_frame *wh;
199 	struct ieee80211_node *ni = NULL;
200 	struct llc *llc;
201 
202 	if (m->m_len < sizeof(struct ether_header)) {
203 		m = m_pullup(m, sizeof(struct ether_header));
204 		if (m == NULL) {
205 			ic->ic_stats.is_tx_nombuf++;
206 			goto bad;
207 		}
208 	}
209 	memcpy(&eh, mtod(m, caddr_t), sizeof(struct ether_header));
210 
211 	ni = ieee80211_find_txnode(ic, eh.ether_dhost);
212 	if (ni == NULL) {
213 		IEEE80211_DPRINTF(ic, IEEE80211_MSG_OUTPUT,
214 			("%s: no node for dst %s, discard frame\n",
215 			__func__, ether_sprintf(eh.ether_dhost)));
216 		ic->ic_stats.is_tx_nonode++;
217 		goto bad;
218 	}
219 	ni->ni_inact = 0;
220 
221 	m_adj(m, sizeof(struct ether_header) - sizeof(struct llc));
222 	llc = mtod(m, struct llc *);
223 	llc->llc_dsap = llc->llc_ssap = LLC_SNAP_LSAP;
224 	llc->llc_control = LLC_UI;
225 	llc->llc_snap.org_code[0] = 0;
226 	llc->llc_snap.org_code[1] = 0;
227 	llc->llc_snap.org_code[2] = 0;
228 	llc->llc_snap.ether_type = eh.ether_type;
229 	M_PREPEND(m, sizeof(struct ieee80211_frame), M_DONTWAIT);
230 	if (m == NULL) {
231 		ic->ic_stats.is_tx_nombuf++;
232 		goto bad;
233 	}
234 	wh = mtod(m, struct ieee80211_frame *);
235 	wh->i_fc[0] = IEEE80211_FC0_VERSION_0 | IEEE80211_FC0_TYPE_DATA;
236 	*(u_int16_t *)&wh->i_dur[0] = 0;
237 	*(u_int16_t *)&wh->i_seq[0] =
238 	    htole16(ni->ni_txseq << IEEE80211_SEQ_SEQ_SHIFT);
239 	ni->ni_txseq++;
240 	switch (ic->ic_opmode) {
241 	case IEEE80211_M_STA:
242 		wh->i_fc[1] = IEEE80211_FC1_DIR_TODS;
243 		IEEE80211_ADDR_COPY(wh->i_addr1, ni->ni_bssid);
244 		IEEE80211_ADDR_COPY(wh->i_addr2, eh.ether_shost);
245 		IEEE80211_ADDR_COPY(wh->i_addr3, eh.ether_dhost);
246 		break;
247 	case IEEE80211_M_IBSS:
248 	case IEEE80211_M_AHDEMO:
249 		wh->i_fc[1] = IEEE80211_FC1_DIR_NODS;
250 		IEEE80211_ADDR_COPY(wh->i_addr1, eh.ether_dhost);
251 		IEEE80211_ADDR_COPY(wh->i_addr2, eh.ether_shost);
252 		IEEE80211_ADDR_COPY(wh->i_addr3, ni->ni_bssid);
253 		break;
254 	case IEEE80211_M_HOSTAP:
255 		wh->i_fc[1] = IEEE80211_FC1_DIR_FROMDS;
256 		IEEE80211_ADDR_COPY(wh->i_addr1, eh.ether_dhost);
257 		IEEE80211_ADDR_COPY(wh->i_addr2, ni->ni_bssid);
258 		IEEE80211_ADDR_COPY(wh->i_addr3, eh.ether_shost);
259 		break;
260 	case IEEE80211_M_MONITOR:
261 		goto bad;
262 	}
263 	if (ic->ic_flags & IEEE80211_F_PRIVACY)
264 		wh->i_fc[1] |= IEEE80211_FC1_WEP;
265 	*pni = ni;
266 	return m;
267 bad:
268 	if (m != NULL)
269 		m_freem(m);
270 	if (ni != NULL)
271 		ieee80211_release_node(ic, ni);
272 	*pni = NULL;
273 	return NULL;
274 }
275 
276 /*
277  * Add a supported rates element id to a frame.
278  */
279 u_int8_t *
280 ieee80211_add_rates(u_int8_t *frm, const struct ieee80211_rateset *rs)
281 {
282 	int nrates;
283 
284 	*frm++ = IEEE80211_ELEMID_RATES;
285 	nrates = rs->rs_nrates;
286 	if (nrates > IEEE80211_RATE_SIZE)
287 		nrates = IEEE80211_RATE_SIZE;
288 	*frm++ = nrates;
289 	memcpy(frm, rs->rs_rates, nrates);
290 	return frm + nrates;
291 }
292 
293 /*
294  * Add an extended supported rates element id to a frame.
295  */
296 u_int8_t *
297 ieee80211_add_xrates(u_int8_t *frm, const struct ieee80211_rateset *rs)
298 {
299 	/*
300 	 * Add an extended supported rates element if operating in 11g mode.
301 	 */
302 	if (rs->rs_nrates > IEEE80211_RATE_SIZE) {
303 		int nrates = rs->rs_nrates - IEEE80211_RATE_SIZE;
304 		*frm++ = IEEE80211_ELEMID_XRATES;
305 		*frm++ = nrates;
306 		memcpy(frm, rs->rs_rates + IEEE80211_RATE_SIZE, nrates);
307 		frm += nrates;
308 	}
309 	return frm;
310 }
311 
312 /*
313  * Add an ssid elemet to a frame.
314  */
315 static u_int8_t *
316 ieee80211_add_ssid(u_int8_t *frm, const u_int8_t *ssid, u_int len)
317 {
318 	*frm++ = IEEE80211_ELEMID_SSID;
319 	*frm++ = len;
320 	memcpy(frm, ssid, len);
321 	return frm + len;
322 }
323 
324 static struct mbuf *
325 ieee80211_getmbuf(int flags, int type, u_int pktlen)
326 {
327 	struct mbuf *m;
328 
329 	IASSERT(pktlen <= MCLBYTES, ("802.11 packet too large: %u", pktlen));
330 #ifdef __FreeBSD__
331 	if (pktlen <= MHLEN)
332 		MGETHDR(m, flags, type);
333 	else
334 		m = m_getcl(flags, type, M_PKTHDR);
335 #else
336 	MGETHDR(m, flags, type);
337 	if (m != NULL && pktlen > MHLEN)
338 		MCLGET(m, flags);
339 #endif
340 	return m;
341 }
342 
343 /*
344  * Send a management frame.  The node is for the destination (or ic_bss
345  * when in station mode).  Nodes other than ic_bss have their reference
346  * count bumped to reflect our use for an indeterminant time.
347  */
348 int
349 ieee80211_send_mgmt(struct ieee80211com *ic, struct ieee80211_node *ni,
350 	int type, int arg)
351 {
352 #define	senderr(_x, _v)	do { ic->ic_stats._v++; ret = _x; goto bad; } while (0)
353 	struct ifnet *ifp = &ic->ic_if;
354 	struct mbuf *m;
355 	u_int8_t *frm;
356 	enum ieee80211_phymode mode;
357 	u_int16_t capinfo;
358 	int has_challenge, is_shared_key, ret, timer;
359 
360 	IASSERT(ni != NULL, ("null node"));
361 
362 	/*
363 	 * Hold a reference on the node so it doesn't go away until after
364 	 * the xmit is complete all the way in the driver.  On error we
365 	 * will remove our reference.
366 	 */
367 	ieee80211_ref_node(ni);
368 	timer = 0;
369 	switch (type) {
370 	case IEEE80211_FC0_SUBTYPE_PROBE_REQ:
371 		/*
372 		 * prreq frame format
373 		 *	[tlv] ssid
374 		 *	[tlv] supported rates
375 		 *	[tlv] extended supported rates
376 		 */
377 		m = ieee80211_getmbuf(M_DONTWAIT, MT_DATA,
378 			 2 + ic->ic_des_esslen
379 		       + 2 + IEEE80211_RATE_SIZE
380 		       + 2 + (IEEE80211_RATE_MAXSIZE - IEEE80211_RATE_SIZE));
381 		if (m == NULL)
382 			senderr(ENOMEM, is_tx_nombuf);
383 		m->m_data += sizeof(struct ieee80211_frame);
384 		frm = mtod(m, u_int8_t *);
385 		frm = ieee80211_add_ssid(frm, ic->ic_des_essid, ic->ic_des_esslen);
386 		mode = ieee80211_chan2mode(ic, ni->ni_chan);
387 		frm = ieee80211_add_rates(frm, &ic->ic_sup_rates[mode]);
388 		frm = ieee80211_add_xrates(frm, &ic->ic_sup_rates[mode]);
389 		m->m_pkthdr.len = m->m_len = frm - mtod(m, u_int8_t *);
390 
391 		timer = IEEE80211_TRANS_WAIT;
392 		break;
393 
394 	case IEEE80211_FC0_SUBTYPE_PROBE_RESP:
395 		/*
396 		 * probe response frame format
397 		 *	[8] time stamp
398 		 *	[2] beacon interval
399 		 *	[2] cabability information
400 		 *	[tlv] ssid
401 		 *	[tlv] supported rates
402 		 *	[tlv] parameter set (FH/DS)
403 		 *	[tlv] parameter set (IBSS)
404 		 *	[tlv] extended supported rates
405 		 */
406 		m = ieee80211_getmbuf(M_DONTWAIT, MT_DATA,
407 			 8 + 2 + 2 + 2
408 		       + 2 + ni->ni_esslen
409 		       + 2 + IEEE80211_RATE_SIZE
410 		       + (ic->ic_phytype == IEEE80211_T_FH ? 7 : 3)
411 		       + 6
412 		       + 2 + (IEEE80211_RATE_MAXSIZE - IEEE80211_RATE_SIZE));
413 		if (m == NULL)
414 			senderr(ENOMEM, is_tx_nombuf);
415 		m->m_data += sizeof(struct ieee80211_frame);
416 		frm = mtod(m, u_int8_t *);
417 
418 		memset(frm, 0, 8);	/* timestamp should be filled later */
419 		frm += 8;
420 		*(u_int16_t *)frm = htole16(ic->ic_bss->ni_intval);
421 		frm += 2;
422 		if (ic->ic_opmode == IEEE80211_M_IBSS)
423 			capinfo = IEEE80211_CAPINFO_IBSS;
424 		else
425 			capinfo = IEEE80211_CAPINFO_ESS;
426 		if (ic->ic_flags & IEEE80211_F_PRIVACY)
427 			capinfo |= IEEE80211_CAPINFO_PRIVACY;
428 		if ((ic->ic_flags & IEEE80211_F_SHPREAMBLE) &&
429 		    IEEE80211_IS_CHAN_2GHZ(ni->ni_chan))
430 			capinfo |= IEEE80211_CAPINFO_SHORT_PREAMBLE;
431 		*(u_int16_t *)frm = htole16(capinfo);
432 		frm += 2;
433 
434 		frm = ieee80211_add_ssid(frm, ic->ic_bss->ni_essid,
435 				ic->ic_bss->ni_esslen);
436 		frm = ieee80211_add_rates(frm, &ic->ic_bss->ni_rates);
437 
438 		if (ic->ic_phytype == IEEE80211_T_FH) {
439                         *frm++ = IEEE80211_ELEMID_FHPARMS;
440                         *frm++ = 5;
441                         *frm++ = ni->ni_fhdwell & 0x00ff;
442                         *frm++ = (ni->ni_fhdwell >> 8) & 0x00ff;
443                         *frm++ = IEEE80211_FH_CHANSET(
444 			    ieee80211_chan2ieee(ic, ni->ni_chan));
445                         *frm++ = IEEE80211_FH_CHANPAT(
446 			    ieee80211_chan2ieee(ic, ni->ni_chan));
447                         *frm++ = ni->ni_fhindex;
448 		} else {
449 			*frm++ = IEEE80211_ELEMID_DSPARMS;
450 			*frm++ = 1;
451 			*frm++ = ieee80211_chan2ieee(ic, ni->ni_chan);
452 		}
453 
454 		if (ic->ic_opmode == IEEE80211_M_IBSS) {
455 			*frm++ = IEEE80211_ELEMID_IBSSPARMS;
456 			*frm++ = 2;
457 			*frm++ = 0; *frm++ = 0;		/* TODO: ATIM window */
458 		} else {	/* IEEE80211_M_HOSTAP */
459 			/* TODO: TIM */
460 			*frm++ = IEEE80211_ELEMID_TIM;
461 			*frm++ = 4;	/* length */
462 			*frm++ = 0;	/* DTIM count */
463 			*frm++ = 1;	/* DTIM period */
464 			*frm++ = 0;	/* bitmap control */
465 			*frm++ = 0;	/* Partial Virtual Bitmap (variable length) */
466 		}
467 		frm = ieee80211_add_xrates(frm, &ic->ic_bss->ni_rates);
468 		m->m_pkthdr.len = m->m_len = frm - mtod(m, u_int8_t *);
469 		break;
470 
471 	case IEEE80211_FC0_SUBTYPE_AUTH:
472 		MGETHDR(m, M_DONTWAIT, MT_DATA);
473 		if (m == NULL)
474 			senderr(ENOMEM, is_tx_nombuf);
475 
476 		has_challenge = ((arg == IEEE80211_AUTH_SHARED_CHALLENGE ||
477 		    arg == IEEE80211_AUTH_SHARED_RESPONSE) &&
478 		    ni->ni_challenge != NULL);
479 
480 		is_shared_key = has_challenge || (ni->ni_challenge != NULL &&
481 		    arg == IEEE80211_AUTH_SHARED_PASS);
482 
483 		if (has_challenge) {
484 			MH_ALIGN(m, 2 * 3 + 2 + IEEE80211_CHALLENGE_LEN);
485 			m->m_pkthdr.len = m->m_len =
486 			    2 * 3 + 2 + IEEE80211_CHALLENGE_LEN;
487 		} else {
488 			MH_ALIGN(m, 2 * 3);
489 			m->m_pkthdr.len = m->m_len = 2 * 3;
490 		}
491 		frm = mtod(m, u_int8_t *);
492 		((u_int16_t *)frm)[0] =
493 		    (is_shared_key) ? htole16(IEEE80211_AUTH_ALG_SHARED)
494 		                    : htole16(IEEE80211_AUTH_ALG_OPEN);
495 		((u_int16_t *)frm)[1] = htole16(arg);	/* sequence number */
496 		((u_int16_t *)frm)[2] = 0;		/* status */
497 
498 		if (has_challenge) {
499 			((u_int16_t *)frm)[3] =
500 			    htole16((IEEE80211_CHALLENGE_LEN << 8) |
501 			    IEEE80211_ELEMID_CHALLENGE);
502 			memcpy(&((u_int16_t *)frm)[4], ni->ni_challenge,
503 			    IEEE80211_CHALLENGE_LEN);
504 			if (arg == IEEE80211_AUTH_SHARED_RESPONSE) {
505 				IEEE80211_DPRINTF(ic, IEEE80211_MSG_AUTH,
506 				    ("%s: request encrypt frame\n", __func__));
507 				m->m_flags |= M_LINK0; /* WEP-encrypt, please */
508 			}
509 		}
510 		if (ic->ic_opmode == IEEE80211_M_STA)
511 			timer = IEEE80211_TRANS_WAIT;
512 		break;
513 
514 	case IEEE80211_FC0_SUBTYPE_DEAUTH:
515 		IEEE80211_DPRINTF(ic, IEEE80211_MSG_AUTH,
516 			("send station %s deauthenticate (reason %d)\n",
517 			ether_sprintf(ni->ni_macaddr), arg));
518 		MGETHDR(m, M_DONTWAIT, MT_DATA);
519 		if (m == NULL)
520 			senderr(ENOMEM, is_tx_nombuf);
521 		MH_ALIGN(m, 2);
522 		m->m_pkthdr.len = m->m_len = 2;
523 		*mtod(m, u_int16_t *) = htole16(arg);	/* reason */
524 		break;
525 
526 	case IEEE80211_FC0_SUBTYPE_ASSOC_REQ:
527 	case IEEE80211_FC0_SUBTYPE_REASSOC_REQ:
528 		/*
529 		 * asreq frame format
530 		 *	[2] capability information
531 		 *	[2] listen interval
532 		 *	[6*] current AP address (reassoc only)
533 		 *	[tlv] ssid
534 		 *	[tlv] supported rates
535 		 *	[tlv] extended supported rates
536 		 */
537 		m = ieee80211_getmbuf(M_DONTWAIT, MT_DATA,
538 			 sizeof(capinfo)
539 		       + sizeof(u_int16_t)
540 		       + IEEE80211_ADDR_LEN
541 		       + 2 + ni->ni_esslen
542 		       + 2 + IEEE80211_RATE_SIZE
543 		       + 2 + (IEEE80211_RATE_MAXSIZE - IEEE80211_RATE_SIZE));
544 		if (m == NULL)
545 			senderr(ENOMEM, is_tx_nombuf);
546 		m->m_data += sizeof(struct ieee80211_frame);
547 		frm = mtod(m, u_int8_t *);
548 
549 		capinfo = 0;
550 		if (ic->ic_opmode == IEEE80211_M_IBSS)
551 			capinfo |= IEEE80211_CAPINFO_IBSS;
552 		else		/* IEEE80211_M_STA */
553 			capinfo |= IEEE80211_CAPINFO_ESS;
554 		if (ic->ic_flags & IEEE80211_F_PRIVACY)
555 			capinfo |= IEEE80211_CAPINFO_PRIVACY;
556 		/*
557 		 * NB: Some 11a AP's reject the request when
558 		 *     short premable is set.
559 		 */
560 		if ((ic->ic_flags & IEEE80211_F_SHPREAMBLE) &&
561 		    IEEE80211_IS_CHAN_2GHZ(ni->ni_chan))
562 			capinfo |= IEEE80211_CAPINFO_SHORT_PREAMBLE;
563 		if (ic->ic_flags & IEEE80211_F_SHSLOT)
564 			capinfo |= IEEE80211_CAPINFO_SHORT_SLOTTIME;
565 		*(u_int16_t *)frm = htole16(capinfo);
566 		frm += 2;
567 
568 		*(u_int16_t *)frm = htole16(ic->ic_lintval);
569 		frm += 2;
570 
571 		if (type == IEEE80211_FC0_SUBTYPE_REASSOC_REQ) {
572 			IEEE80211_ADDR_COPY(frm, ic->ic_bss->ni_bssid);
573 			frm += IEEE80211_ADDR_LEN;
574 		}
575 
576 		frm = ieee80211_add_ssid(frm, ni->ni_essid, ni->ni_esslen);
577 		frm = ieee80211_add_rates(frm, &ni->ni_rates);
578 		frm = ieee80211_add_xrates(frm, &ni->ni_rates);
579 		m->m_pkthdr.len = m->m_len = frm - mtod(m, u_int8_t *);
580 
581 		timer = IEEE80211_TRANS_WAIT;
582 		break;
583 
584 	case IEEE80211_FC0_SUBTYPE_ASSOC_RESP:
585 	case IEEE80211_FC0_SUBTYPE_REASSOC_RESP:
586 		/*
587 		 * asreq frame format
588 		 *	[2] capability information
589 		 *	[2] status
590 		 *	[2] association ID
591 		 *	[tlv] supported rates
592 		 *	[tlv] extended supported rates
593 		 */
594 		m = ieee80211_getmbuf(M_DONTWAIT, MT_DATA,
595 			 sizeof(capinfo)
596 		       + sizeof(u_int16_t)
597 		       + sizeof(u_int16_t)
598 		       + 2 + IEEE80211_RATE_SIZE
599 		       + 2 + (IEEE80211_RATE_MAXSIZE - IEEE80211_RATE_SIZE));
600 		if (m == NULL)
601 			senderr(ENOMEM, is_tx_nombuf);
602 		m->m_data += sizeof(struct ieee80211_frame);
603 		frm = mtod(m, u_int8_t *);
604 
605 		capinfo = IEEE80211_CAPINFO_ESS;
606 		if (ic->ic_flags & IEEE80211_F_PRIVACY)
607 			capinfo |= IEEE80211_CAPINFO_PRIVACY;
608 		if ((ic->ic_flags & IEEE80211_F_SHPREAMBLE) &&
609 		    IEEE80211_IS_CHAN_2GHZ(ni->ni_chan))
610 			capinfo |= IEEE80211_CAPINFO_SHORT_PREAMBLE;
611 		*(u_int16_t *)frm = htole16(capinfo);
612 		frm += 2;
613 
614 		*(u_int16_t *)frm = htole16(arg);	/* status */
615 		frm += 2;
616 
617 		if (arg == IEEE80211_STATUS_SUCCESS)
618 			*(u_int16_t *)frm = htole16(ni->ni_associd);
619 		frm += 2;
620 
621 		frm = ieee80211_add_rates(frm, &ni->ni_rates);
622 		frm = ieee80211_add_xrates(frm, &ni->ni_rates);
623 		m->m_pkthdr.len = m->m_len = frm - mtod(m, u_int8_t *);
624 		break;
625 
626 	case IEEE80211_FC0_SUBTYPE_DISASSOC:
627 		IEEE80211_DPRINTF(ic, IEEE80211_MSG_ASSOC,
628 			("send station %s disassociate (reason %d)\n",
629 			ether_sprintf(ni->ni_macaddr), arg));
630 		MGETHDR(m, M_DONTWAIT, MT_DATA);
631 		if (m == NULL)
632 			senderr(ENOMEM, is_tx_nombuf);
633 		MH_ALIGN(m, 2);
634 		m->m_pkthdr.len = m->m_len = 2;
635 		*mtod(m, u_int16_t *) = htole16(arg);	/* reason */
636 		break;
637 
638 	default:
639 		IEEE80211_DPRINTF(ic, IEEE80211_MSG_ANY,
640 			("%s: invalid mgmt frame type %u\n", __func__, type));
641 		senderr(EINVAL, is_tx_unknownmgt);
642 		/* NOTREACHED */
643 	}
644 
645 	ret = ieee80211_mgmt_output(ifp, ni, m, type);
646 	if (ret == 0) {
647 		if (timer)
648 			ic->ic_mgt_timer = timer;
649 	} else {
650 bad:
651 		ieee80211_release_node(ic, ni);
652 	}
653 	return ret;
654 #undef senderr
655 }
656 
657 void
658 ieee80211_pwrsave(struct ieee80211com *ic, struct ieee80211_node *ni,
659 		  struct mbuf *m)
660 {
661 	/* Store the new packet on our queue, changing the TIM if necessary */
662 
663 	if (IF_IS_EMPTY(&ni->ni_savedq)) {
664 		ic->ic_set_tim(ic, ni->ni_associd, 1);
665 	}
666 	if (ni->ni_savedq.ifq_len >= IEEE80211_PS_MAX_QUEUE) {
667 		IF_DROP(&ni->ni_savedq);
668 		m_freem(m);
669 		if (ic->ic_if.if_flags & IFF_DEBUG)
670 			printf("%s: station %s power save queue overflow"
671 			       " of size %d drops %d\n",
672 			       ic->ic_if.if_xname,
673 			       ether_sprintf(ni->ni_macaddr),
674 			       IEEE80211_PS_MAX_QUEUE,
675 			       ni->ni_savedq.ifq_drops);
676 	} else {
677 		/* Similar to ieee80211_mgmt_output, store the node in
678 		 * the rcvif field.
679 		 */
680 		IF_ENQUEUE(&ni->ni_savedq, m);
681 		m->m_pkthdr.rcvif = (void *)ni;
682 	}
683 }
684 
685